There have been developed various combined separation systems for rapid phase separation. Certain attempts have been made to make use of the so called "Boycott" effect, which requires inclination of the tube walls at a certain angle to the vector of the centrifugation force in order to make the phase separation more efficient. An example of a system employing the Boycott effect is described in the article "Automated Centrifuge Technology"--Laboratory Automation News--vol. 1 No. Oct. 4, 1996. The device described in this article employs switchable cam-like mechanism for displacement the tube during centrifugation.
There are known also other centrifugation assemblies utilizing the Boycott effect, e.g. as disclosed in U.S. Pat. No. 5,584,790 assigned to Beckman Instruments Inc.. This assembly employs a spring-loaded linkage system for inclination holders carrying the tubes and thus to misalign the tubes with the vector of the centrifugation force.
The other example of a centrifugation assembly employing the Boycott effect can be found in U.S. Pat. No. 5,588,946 assigned to Johnson & Johnson Clinical Diagnostics, Inc. In this assembly a patient sample tube is spun while non-aligned with the centrifugation force to allow phase separation and then while aligned to allow any gel present between the separated phases to seal.
Unfortunately the constructions of the above assemblies are not suitable for implementation in a conventional swing-out bucket centrifuge in which a large number of tubes should be rotated. Furthermore the assemblies mentioned above are not capable of developing sufficient phase separation in large number of sample tubes.